How severe is CVE-2026-27446?

CVE-2026-27446 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-27446?

CVE-2026-27446 affects the following packages: org.apache.activemq:artemis-server (Maven), org.apache.artemis:artemis-server (Maven). Ecosystems affected: Maven.

How do I fix CVE-2026-27446?

No patched version of org.apache.activemq:artemis-server has shipped for CVE-2026-27446 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.

How do I detect CVE-2026-27446 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.activemq:artemis-server. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2026-27446 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-27446?

O3 pinpoints whether CVE-2026-27446 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2026-27446 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-27446 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-27446?

CVE-2026-27446 has an EPSS (Exploit Prediction Scoring System) score of 8.3%, placing it in the 94th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was CVE-2026-27446 published, and has it been updated?

CVE-2026-27446 was published on March 4, 2026 and was last updated on May 21, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2026-27446: artemis-server (Critical 9.8)

EPSS Exploitation Probability

via FIRST.org ↗

8.3%probability of exploitation in next 30 days

Lower Risk94th percentile+8.18%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

2 pkgs affected

☕org.apache.activemq:artemis-server☕org.apache.artemis:artemis-server

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

Missing Authentication for Critical Function (CWE-306) vulnerability in Apache Artemis, Apache ActiveMQ Artemis. An unauthenticated remote attacker can use the Core protocol to force a target broker to establish an outbound Core federation connection to an attacker-controlled rogue broker. This could potentially result in message injection into any queue and/or message exfiltration from any queue via the rogue broker. This impacts environments that allow both:

incoming Core protocol connections from untrusted sources to the broker
outgoing Core protocol connections from the broker to untrusted targets

This issue affects:

Apache Artemis from 2.50.0 through 2.51.0
Apache ActiveMQ Artemis from 2.11.0 through 2.44.0.

Users are recommended to upgrade to Apache Artemis version 2.52.0, which fixes the issue.

The issue can be mitigated by one of the following:

Remove Core protocol support from any acceptor receiving connections from untrusted sources. Incoming Core protocol connections are supported by default via the "artemis" acceptor listening on port 61616. See the "protocols" URL parameter configured for the acceptor. An acceptor URL without this parameter supports all protocols by default, including Core.
Use two-way SSL (i.e. certificate-based authentication) in order to force every client to present the proper SSL certificate when establishing a connection before any message protocol handshake is attempted. This will prevent unauthenticated exploitation of this vulnerability.
Implement and deploy a Core interceptor to deny all Core downstream federation connect packets. Such packets have a type of (int) -16 or (byte) 0xfffffff0. Documentation for interceptors is available at https://artemis.apache.org/components/artemis/documentation/latest/intercepting-operations.html .

Affected Packages

2 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.apache.activemq:artemis-server`	≥ 2.11.0	No fix
☕Maven	`org.apache.artemis:artemis-server`	≥ 2.50.0&&< 2.52.0	2.52.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.activemq:artemis-server. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
No patched version of org.apache.activemq:artemis-server has shipped for CVE-2026-27446 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-27446 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2026-27446. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Missing Authentication for Critical Function (CWE-306) vulnerability in Apache Artemis, Apache ActiveMQ Artemis. An unauthenticated remote attacker can use the Core protocol to force a target broker to establish an outbound Core federation connection to an attacker-controlled rogue broker. This could potentially result in message injection into any queue and/or message exfiltration from any queue via the rogue broker. This impacts environments that allow both: - incoming Core protocol connections from untrusted sources to the broker - outgoing Core protocol connections from the broker to unt

O3 Security · Impact-Aware SCA

Is CVE-2026-27446 in your dependencies?

O3 detects CVE-2026-27446 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works

CVE-2026-27446